这个谷歌文档页面的当前内容是:
替代文字 http://www.deviantsart.com/upload/i9k01q.png
但是,当使用以下 PHP fopen()脚本阅读此页面时,我得到了一个较旧的缓存版本:
(来源:deviantsart.com)
我尝试了这个问题中提出的两种解决方案(随机属性和使用 POST),我也尝试了clearstatcache()但我总是得到网页的缓存版本。
为了使 fopen() 返回网页的当前版本,我必须在以下脚本中进行哪些更改?
<?php
$url = 'http://docs.google.com/View?id=dc7gj86r_32g68627ff&rand=' . getRandomDigits(10);
echo $url . '<hr/>';
echo loadFile($url);
function loadFile($sFilename) {
clearstatcache();
if (floatval(phpversion()) >= 4.3) {
$sData = file_get_contents($sFilename);
} else {
if (!file_exists($sFilename)) return -3;
$opts = array('http' =>
array(
'method' => 'POST',
'content'=>''
)
);
$context = stream_context_create($opts);
$rHandle = fopen($sFilename, 'r', $context);
if (!$rHandle) return -2;
$sData = '';
while(!feof($rHandle))
$sData .= fread($rHandle, filesize($sFilename));
fclose($rHandle);
}
return $sData;
}
function getRandomDigits($numberOfDigits) {
$r = "";
for($i=1; $i<=$numberOfDigits; $i++) {
$nr=rand(0,9);
$r .= $nr;
}
return $r;
}
?>
添加:取出$opts和$context也会给我一个缓存页面:
function loadFile($sFilename) {
if (floatval(phpversion()) >= 4.3) {
$sData = file_get_contents($sFilename);
} else {
if (!file_exists($sFilename)) return -3;
$rHandle = fopen($sFilename, 'r');
if (!$rHandle) return -2;
$sData = '';
while(!feof($rHandle))
$sData .= fread($rHandle, filesize($sFilename));
fclose($rHandle);
}
return $sData;
}
添加:这个发送 Firefox 用户代理的curl脚本也返回缓存的版本:
<?php
$url = 'http://docs.google.com/View?id=dc7gj86r_32g68627ff';
//$user_agent = 'Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)';
$user_agent = 'Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3 (.NET CLR 3.5.30729)';
$ch = curl_init();
//curl_setopt($ch, CURLOPT_COOKIEJAR, "/tmp/cookie");
//curl_setopt($ch, CURLOPT_COOKIEFILE, "/tmp/cookie");
curl_setopt($ch, CURLOPT_URL, $url );
curl_setopt($ch, CURLOPT_FAILONERROR, 1);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch, CURLOPT_TIMEOUT, 15);
curl_setopt($ch, CURLOPT_USERAGENT, $user_agent);
curl_setopt($ch, CURLOPT_VERBOSE, 0);
echo curl_exec($ch);
?>